Poly(ADP-ribose) polymerase 9 (PARP9)

Poly(ADP-ribose) polymerase 9 (PARP9) is a member of the PARP enzyme family functionally classified as a mono-ADP-ribosyltransferase, though it was initially thought to be catalytically inactive. PARP9 forms a complex with the E3 ubiquitin ligase DTX3L and plays crucial roles in DNA damage repair, innate immune signaling (including as a non-canonical viral RNA sensor to induce type I interferon via the PI3K/AKT3 pathway), and regulation of pro-inflammatory cytokine responses, especially by modulating STAT1 phosphorylation. PARP9 is implicated in antiviral immunity, inflammation, and several malignancies including B-cell lymphomas, and its expression is dynamically regulated during infection and immune responses[1][2][3].

Other names

Protein mono-ADP-ribosyltransferase PARP9PARP9BALBAL1ARTD9PARP-9B aggressive lymphoma proteinADP-ribosyltransferase diphtheria toxin-like 9

NAD(+)-dependent mono-ADP-ribosylation of proteins (in complex with DTX3L); Binding to viral dsRNA and activating PI3K/AKT3 pathway to trigger type I interferon production independently of canonical MAVS pathways; Regulation of STAT1 phosphorylation by suppressing PARP14-mediated ADP-ribosylation